Fluid handling machine with axial pressure control

ABSTRACT

In a fluid handling machine, such as a pump or motor, or a hydrostactic transmission, a presser body abuts at one end a rotor and forms at the other end outer and inner annular pressure chambers with a housing part. The outer periphery of the outer pressure chamber and the inner periphery of the inner pressure chamber are coaxial with the rotor, but slidingly engaged cylindrical face portions along the inner periphery of the outer pressure chamber and outer periphery of the inner pressure chamber have a common axis eccentric to, and parallel with the rotor axis so that the widths of the effective annular pressure faces of the outer and inner pressure chambers varies. Fluid at different pressures is located in the inner and outer pressure chambers, and pressure forces are transmitted from the pressure chambers to the rotor to press the rotor against a staionary control face of the housing.

United States Patent 1191 Eickmann Feb, 12, 1974 [541 FLUID HANDLING MACHINE WITH AXIAL 3,280,757 10/1966 Eickmann 91/498 PRESSURE CONTROL 3,090,361 5/1963 Orshansky i 2,827,859 3/1958 Crane 91/491 Inventor: KarlEickmann, 2420Issh1k1, 2,993,339 7/1961 Timms 60/53 B l-layama-machi, Kanagawa-ken, Japan FOREIGN PATENTS OR APPLICATIONS [22] Filed: Nov. 16 1970 1,224,344 6/1960 France 91/505 App]. No.: 89,804

Related U.S. Application Data Continuation-impart of Ser. No. 876,177, Dec. 2, 1969, Pat. No. 3,561,328, which is a continuation of Ser. No. 689,108, Dec. 8, 1967, abandoned.

Foreign Application Priority Data Dec. 8, 1966 Germany 902159 U.S. CI 91/485, 91/487, 91/492 Int. Cl. F011) 1/00 Field of Search 91/492, 484, 485, 487, 491,

Primary Examiner-William L. Freeh Assistant ExaminerG. LaPointe Attorney, Agent, or Firm-Michael S. Striker [57] ABSTRACT In a fluid handling machine, such as a pump or motor, or a hydrostactic transmission, a presser body abuts at one end a rotor and forms at the other end outer and inner annular pressure chambers with a housing part. The outer periphery of the outer pressure chamber and the inner periphery of the inner pressure chamber are coaxial with the rotor, but slidingly engaged cylindrical face portions along the .inner periphery of the outer pressure chamber and outer periphery of the References Cited inner pressure chamber have a common axis eccentric UNITED STATES PATENTS to, and parallel with the rotor axis so that the widths 3,122,971 3/1964 Russell 91 /485 9 the effective afmular of P and 3,155,010 11/1964 Johnson at 81m 91/485 Inner pressure chambers vanes. Flu1d at different pres- 2,38l,741 8/1945 Grosser 91/484 S is located in the inner and outer pressure cham- 2,895,426 7/1959 Orshansky, Jr. 91/485 bers, and pressure forces are transmitted from the 2,972,961 2/ 1961 Clark 91/485 X pressure chambers to the rotor to press the rotor Relllke a face of the 3,257,959 6/1966 Budzich 417/217 X 3,092,036 6/1963 Creighton.., 91/487 8 Claims, 18 Drawing Figures 29 I 2 7 a 9 2 g 27 l3 l2 J 41, 4 1,2. /0 3 W l9 4 l 70 5 V 6 I a /8 PATENIEU FEB] 2 I974 SHEET 3 OF 4 FLUID HANDLING MACHINE WITH AXIAL PRESSURE CONTROL CROSS-REFERENCES TO RELATED APPLICATIONS This application is a continuation-in-part application of my copending application Ser. No. 876,177, now Patent No. 3,561,328, which is a continuation of my patent application Ser. No. 689,108 filed Dec. 8, 1967, now abandoned.

BACKGROUND OF THE INVENTION This invention is related to improvements in machines of the type with radial variable displacement chambers used as pumps, motors, compressors, engines and transmissions wherein the fluid flow from or into the displacement chambers is substantially in the axial direction. In such machines, the rotor which contains the displacement chambers, cooperates with at least one control body, which is provided with control ports for the transfer of fluid to or away from the rotor.

Mating smooth control faces are provided between the rotor and the control body to permit relative movement between the two. A thin fluid film is maintained between the faces so that the surfaces do not weld together. The control faces are pressed tightlytogether so that leakage through the clearance remains small.

The problem in such machines, however, is that the pressure of the fluid acting along the axis against the rotor is not in all cases and at all times locationally in suitable balance with the pressure acting from an opposite location of another clearance between the control faces. At some other locations the pressure action from the fluid-containing chamber is too big and from another, too small, so that the fluid film between the control faces tends to have different thickness at different local places.

In machines of this type the size of the bearings or the control body thereof may restrict the adjustment of the stroke of the machine and its displacement volume, thereby limiting the power of the machine.

SUMMARY OF THE INVENTION According to this invention the above-mentioned short-comings are overcome as follows:

A pair of fluid containing pressure chambers are provided at one end of a presser member which is movably along the shaft of the machine againstthe rotor or control body. There is a medial seal between both pressure chambers in the form of a circular ring which is eccentric to a degree about equal to the eccentricity of the machine, i.e., the amount of the inner and outer points of movement of the displacement chamber means in such a way that the chamber-s have a wide portion and a narrow portion with the wide portion of one being aligned adjacent with the narrow portion of the other. The fluid-containing chambers communicate with a high pressure port and a low pressure port-on the control face. The wider portion of the high pressurechamber lies substantially in line with the high pressure control port and the smaller portion of the chamber is in line with the low pressure port.

A passage extends from each high pressure port into the wider portion of each of the chambers. Both chambers are sealed from each other. They are, via the passages, automaticallyfilled with fluid which acts against the presser member in order to press the control faces together. At any instant there will be a wider portion of the fluid-containing chamber aligned with a high pressure control port and a smaller portion of the fluidcontaining chamber aligned with a low pressure control port. The invention thereby achieves a suitable balance of the local forces in the areas of the control faces and results in a uniform pressing of the rotary and stationary control faces against each other. Safe operation of the machine is thereby, according to this invention, assured.

A second object of the invention is to construct all parts in such a way that a large displacement stroke in the machine will be permitted so that the power and efficiency of the machine will become maximized. This is accomplished by having the outer faces of the various parts formed with radii around an axis spaced from the main axis thus giving'the parts an oblong shape and permitting a greater adjustment of the stroke, which was heretofore impossible when cylindrical portions and parts were provided in conventional machines.

A third counteracting generally circular annular chamber on the opposite end or shoulder of the presser body can be provided to help adjust or balance the axial forces acting on the rotor. By this means the forces of the first two fluid-containing chambers of the invention can be counterbalanced in an exactly calculated and predetermined manner.

Another object of this invention is to assemble at least two fluid-handling devices one of which may be a pump and the other a motor, in such a manner the shaft of one extends through the other.

A fluid line may extend through the central shaft. If a shaft ofa pump so extends through a motor then a differential gear can be provided on the end of the motor and pump shafts and the outgoing shaft of the differential can transfer mechanical power out of the transmission. If pump and. motor are at full displacement, the output shaft may stand still, because the motor might revolve contrary to the pump. With the'pump at minimum displacement and the motor stopped, the output shaft may be used to transfer power to the pump shaft. If the pump is driven with full eccentricity in another direction, the velocity of the output shaft of the end differential can be doubled.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view through a fluidhandling device designed according to this invention;

FIG. 2 is a partial cross-sectional view through FIG. 1 taken along the line II-II;

FIG. 3 is a partial cross-sectional view through FIG. 1 taken along the line III-III;

FIG.\ 4 is an explanatory schematic combining the features shown in FIGS. 2 and 3;

FIG. 5 is a partial cross-sectional view through FIG. 1 taken along the line V-V;

FIG. 6 is a longitudinal sectional view through another embodiment of the invention wherein a pump and a motor are combined with one extending partially through the other;

FIG. 7 shows a portion of FIG. 6;

FIG. 8 is a longitudinal sectional view along line VIII- -VIII of FIG. 7;

FIG. 9 is a cross-sectional view through FIG. 7 taken along the line IXIX;

FIG. 10 is an explanatory schematic of FIG. 9;

FIG. II is a cross-sectional view through FIG. 7 taken partially along the line XIXI;

FIG. 12 is a cross-sectional view through FIG. 7 taken partially along the line XII-XII;

FIG. 13 is an explanatory diagram for explaining the arrangement of FIG. 7;

FIG. 14 is a cross-sectional view through FIG. 7 taken partially along the line XIV-XIV;

FIG. 15 is a cross-sectional view of FIG. 6 taken along the line XV-XV;

FIG. 16 is a longitudinal section view through another embodiment of the invention;

FIG. 17 is a cross-sectional view through FIG. 16 taken along the line XVIIXVII; and

FIG. 18 is a cross-sectional or longitudinal view through a portion of an assembly in a machine of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Housing 30 of the group or fluid-handling device of FIG. 1 has covers 12 and 29 which have a pair of fluid passages 858, 860 or 658, 660, respectively, ending in threaded ports 57, 59 or 657, 659, respectively, one of which is an entrance line and the other is an exhaust line. Rotor I is carried on shaft which is borne in bearings 11 (see FIG. 5) and is movable therein along the axis to a limited extent. Control body 3 with control ports 33 and 34 (see FIG. 3) and control body 4 with similar control ports, one of which is shown at 44 (FIG. I) are placed at each end of rotor l.

Fluid-handling chambers 14 and arranged in two adjacent chamber groups, are provided in rotor 1. Pistons I6 and 17 move therein as the rotor revolves. Piston l6 and 17 are guided by stroke actuator 24 carried in support ring 26 which in turn is borne in bearings 27. Guideshoes 18 are provided between the acturor 24 and pistons 16 or 17. Ridges 23 in shoes 18, and mating slot 25 in actuator 24 are provided to aid in aligning the members.

A cylindrical thrust member 2 is provided according to this invention on one side of the rotor and is slidably contained within the bore of the housing 12. Control body 4 bears against front cover 29 and the passages through cover 29 communicate to the control ports in control body 4. Rotor passages 19 extend from working chambers 15 in rotor l, and rotor passages 19 extend from chambers 14, and communicate with the respective control ports of the control bodies 3 and 4. The opposite surface of control body 3 bears against the presser member 2 and both'bodies are movably fixed together to move along the axis of the shaft.

At the opposite end of presser member 2, two fluidcontaining chambers 5 and 6 are provided. Passage 31 (shown in FIGS. 2 and 5) and control port 33 (FIGS. 3 and 4) provide a passageway fluid-containing chamber 5 (FIGS. 1 and 2) and passage 32 extends through presser member 2 from control port 34 (FIGS. 2 and 3) into fluid-containing chamber 6 (FIGS. 1 and 3).

Fluid-containing pressure chambers 5 and 6 are sealed against each other by seal means 9. They are cylindrically configurated, but the axis of the outer surface of chamber 5 and the inner surface of chamber 6 are spaced from the center axis of the outer surface of chamber 6 and inner surface of chamber 5 by an eccentric distance which is about equal to the strokeadjustment capability of the machine. The axis of the outer surface of chamber 6 and the inner surface of chamber 5 are aligned with the rotor axis. This eccentricity is shown clearly in FIGS. 2 and 4 by reference number 37. Thus each chamber 5 and 6 forms, according to this invention an enlarged portion in a direction which is normal to the plane through the outer and inner displacement deadpoints of the machine, and in the opposite direction thereto a narrow portion, in chambers 5 and 6. The enlarged portions are located oopositely to each other and so are the narrowed portions W Y With reference to FIG. 4, reference numbers 35 and 36 demonstrate the closing arcs between the control ports 33 and 34 whenever the rotor passages 19 pass over the inner or outer control ports during displacement. The larger portion of chamber 6, when viewed from flange 13, of control port 34 and the narrower portion of chamber 5 lies in front of control port 34. The larger portion of chamber 5 lies in front of control port 33 and so does the narrower portion of chamber 6. In the middle between the larger and narrower portions of chambers 5 and 6 are two medial portions of about equal size and they lie in front of closing are 35 and 36 respectively. As shown in FIG. 4 the larger portion of chamber 5 is considerably larger in area than the opening of port 33 such that the fluid therein acts on member 2 and presses it against body 3 and rotor 1, with a small amount of force on the right and left side of member 2 (as illustrated in FIG. 4). The same applies to the other side of FIG. 4, where a large portion of chamber 6 covers port 34 with a similar result. Thus, according to this structure of the invention, because of the fluid contained in chambers 5 or 6, member 2, and thereby the respective control bodies, will at all times be about equally pressed against the neighboring body or surface with a force that is in excess of the counter acting thrust occassioned by the fluid contained in passageways 19, which force will automatically vary with the fluid pressure required to be contained in the chambers. Therefore, safe operation of the machine is aided by maintaining a uniform film thickness of fluid on the faces of the control bodies 3 and 4.

The bigger the diameter of bearings 27, the greater is the friction loss because of the bearings, and the efficiency of the machine is reduced. The bearings 27 and their support rings 26 are therefore made as small in diameter as possible. As the adjustment device of the machine moves the stroke adjustment means 28 and stroke actuators upwards or downwards in FIG. 1 or in other words, as the eccentricity of actuator 24 is increased, the inner faces of rings 26 will tend to touch against the outer faces of the respective cylindrical portions within the inner space of the ring 26. A further increase of eccentricity and stroke is thus not possible.

According to this invention as shown in FIG. 5, the outer faces of parts or portions within the inner space defined by ring means 26, Le, the respective control bodies 3 and 4 and portions of cover 29 and a portion of thrust member 2, are oblong in cross section and bounded by two part-circular surfaces in such a way as to give more room for movement of the stroke adjustment means 28. The outer surfaces of these parts are formed with a radius on a line which is displaced, see reference numbers 38 and 39, from the center line of the respective part. Face 777 is an arcuate surface of member 2 having a radius on line 39, and face 778 is an aracuate surface having a radius on line 38. Faces 777 and 778 have the configuration of the inner face 779 of ring 26. The result that the inner face 779 can now be moved closer to the axis of the machine. The stroke and displacement volume, and the power, of the new machine is thereby greatly increased. In actual de sign, this increase of stroke, displacement and power can amount up to 40 percent. At the same time the weight of the machine can be decreased because the diameter of the bearings can be kept small as can the weight of the neighboring parts.

Referring to FIG. 6, it is possible to extend a shaft of one of the machines through another one. Two fluidhandling devices have the same axis and are mounted in line with one another. One acts preferably as a pump on the left side of FIG. 6, and the other as a motor on the right, or, they together form a transmission. The same reference numbers are used in FIG. 6 as are used in FIGS. 1 to 5 to identify similar parts except that in the case of the left side of FIG. 6, the number is in the l00s and the case of the right side of FIG. 6, the number is in the 2 to 3 hundreds. Pump 101 is a radial piston pump, while motor 201 is a vane-type pump. Shaft .149 of motor 101 is provided with center bore 148 which extends through the whole length of the shaft 149, and in which shaft 147 or pump 101 is located. The displacement chambers 114, 115, 314, and 315 are located radially about shafts I47 and 149 as are the pistons 116, 117, 216 and 217 and the stroke actuators.

It is possible to take the transmission of the power either from shaft 147 which has one speed, or to take the power from the motor shaft 149 which may have any other speed, torque or rotation direction depending on the stroke of the pump and, motor. It is even possible to take fluid power from passage 146 through shaft 147. An additional shaft could extend through bore 146. Such a shaft, not shown in the drawing, could be used for power transfer or for transfer of a command control or the drive of a control pump, or the like.

A differential gear can be placed on the end of the transmission. One shaft, for example, the motor shaft, would then drive one input rotary member of the differential and the pump shaft or shaft 147, extending through, could drive the other input rotary member of the differential gear. The output shaft or output rotatable member of the differential gear would then have different torque and revolution, depending not solely on the rotational movement'of the pump shaft but on the combination of the motion, whether at rest or not, of pump shaft 147 and motor shaft 149.

Member 245 is located in the middle between pump I01 and motor 201 and it can move along the axis to a limited extent to allow the rotors and control bodies of the pump and motor to be suitably held together or pressed together by the fluid-containing pressure chambers 105 and 106, positioned on the left end of pressure member 2. Medial member 245 and housing 112 may be provided with passages 161, 162, 163 and 164 (see FIG. forthe transfer of fluid from pump 101 to motor 201 and vice versa.

Passages 161 and 162 extend through the medial member 145 (in FIG. 15) which is prevented from rotation by key 165. One of the passages 161 and 162 is a passage for passing fluid from the pump to the motor and the other for passing fluid from the motor back to the pump. Passages 163 and 164 extend from the pump through the housing 112 to the motor and one acts to pass fluid from the pump to the motor and the other acts to transfer fluid from the motor to the pump. These passages through housing 112 can serve to cool the fluid. As shown in FIGS. 6, 7 and 9, the machine comprises housing means having a stepped inner annular shoulder surface 107; rotor means 101, 201 supported in said housing means for rotation about a rotor axis and for limited axial movement and having a rotary control face 221, said rotor means having working chambers, and movable displacement means 116 in said working chambers having outer ends; actuator means 124 having an inner annular surface engaged by said outer ends, said inner annular surface having an axis eccentric to said rotor axis so that said displacement means are moved in said working chambers for increasing and decreasing the volume of the respective working chamber, said displacement means 116 assuming outer and inner end positions when moving through a predetermined plane passing through said axes; and a presser body means 102 mounted in said housing means for limited axial movement, and having at one end thereof a stepped outer annular shoulder surface 109a cooperating with said stepped inner annular shoulder surface of said housing means to form radially outer 106 and inner 105 annular pressure chambers containing high pressure fluid and low pressure fluid, respectively, for urging the other end of said presser body 2, 102 against said rotor means 101, 210, said other end having a stationary control face which is pressed against said rotary control face, said outer annular pressure chamber 106 being bounded at its outer periphery by pairs of cylindrical first face portions of said outer and inner stepped annular shoulder surfaces 107, 108, said first face portions being coaxial with said rotor axis and slidingly engaging each other, said housing means having a cylindrical housing surface 108 bounding the inner circumference of said inner annular pressure chamber 105, and said inner and outer annular pressure chambers 105, 106 being separated by second slidingly engaged cylindrical face portions having a common axis eccentrically spaced from said rotor axis in a plane perpendicular to said predetermined plane passing through said rotor axis, said outer and inner stepped annular shoulder surfaces including outer and inner effective pressure faces 106b, b located in planes perpendicular to said rotor axis between said slidingly engaged first and second cylindrical face portions 106, 108 and said cylindrical housing surface and having circumferentially varying widths so that narrow portions of said inner and outer pressure faces 105b, l06b are located adjacent the wide portions of said outer and inner pressure faces, respectively. FIG. 10 shows, in a manner similar to FIG. 4, a schematic view of the two fluid-containing chambers I05 and 106. Reference number 108 shows the circular inner face of chamber 105 and reference 107'shows the circular outer face of chamber 106. Faces 107 and 108 are concentric. The medial sealing face 109 between chambers 105 and 106 is eccentric to faces 107 and 108. The eccentricity is indicated by reference number 137 and e. As a result of this eccentricity, the chambers 105 and 106 form a narrow portion and a wider portion and the respective narrow and wide portions of the two chambers are oppositely located.

For design reasons, it is desirable to extend a portion of housing 112 towards the rotor of the machine in order to have it carry the shaft bearings 111. Such bearings must have a certain minimum diameter which tends to limit the size of the fluid-containing pressure chambers 105 and 106. If the cross-sectional area of the fluid-containing chambers 105 and 106 were too small the machining of them would be difficult. If the radial dimensions through the fluid-containing spaces 105 and 106 are too large, however, with a too large of a cross-sectional area, the pressing force along the axis by the fluid in the chambers can be too great.

It is therefore desirable, in accordance with this invention, to provide a means for counteracting the fluid force produced by the fluid contained in chambers 105 and 106. To achieve this, a fluid-containing counterbalancing chamber 140 and/or a closure member 144 is disposed to act oppositely thereto. A passage is provided to transfer fluid into said chamber 140. As will be seen from FIGS. 7 and 8, a shoulder is provided on member 102, against which fluid chamber 140 can act.

The outer face and also the inner face of fluidcontaining counteracting chamber 140 can be circular to simplify its manufacture. Seals 141 can be provided. Cover means 144, for chamber 140 can also be concentric and circularly enclose chamber 140 in one axial direction. Cover 144 may be retained in housing 112 by suitable retaining means. Thus, presser body 102 can move to a little extent along the axis between chambers 105 and 106, and 140, thereby enabling it to move more closely to the rotor 101 or away therefrom within the limits of the axial extensions of the chambers 105, 106 and 140. Presser body 102 can be hollow to permit cover portion 155 to extend into it and retain bearings 111 and shaft 110 (FIG. 8). A passage means and fluid chamber 154 for transferring of fluid out of one of the chambers 105, 106 or 140 through shaft 110 and into passage 142 therein can be provided, especially for automatic control purposes.

FIG. 9 shows fluid containing chambers 105 and 106 with passages 160 and 158 which extend through member 102. In FIG. 13 the dotted line 241 shows the inner face of the counteracting chamber 140 in order to determine the axial thrust of chamber 105 or 106, it is necessary to determine the difference between the areas encompassed by face 141 and face 107, i.e., the cross-sectional area of chamber 105 or 106 minus the effective cross-sectional area of counteracting chamber 140.

Because the medial seal 109 between chambers 105 and 106 is eccentric, as shown in FIG. 13, there are overlapping cross-sectional areas 240, 540, 440, 740,

340, 640, 840 and 940 so dimensioned that they appropriately cover different areas of the control faces and the control ports therein. Thus, a fluid pressure balance can be realized over the entire area of the control ports and control faces to aid in the control of the fluid clearances of the machine.

In FIG. 11, the locations of passages 133 and 134 through control body 3 (FIG. 1) are illustrated. Also shown are closing arcs and the pins 43 for preventing rotation of control body 3. FIG. 11 also shows how shaft 110 is located inside of presser member 2 and the location of passage 142 inside of shaft 110. It should also be noted that there are ribs between the portions of the control ports 133 and 134 in order to maintain the radial stability and total rigidity of the control bodies.

FIG. 12 illustrates in cross-section the location of the rotor passages 119 from chambers 14 (FIG. 1) in the rotor 101.

FIG. 14 shows in cross-section view how the outer faces and the control passageways of presser member 2 (or 102) are formed in order to accommodate its oblong shape. It is desirable to locally divide passageways 131 and 132 by ribs as shown. These ribs help provide the requisite radial and overall stability and rigidity. The respective portions of passages 131 and 132 come together at the ends of the thrust member to form single outlet or inlet.

FIGS. 7 and 8 illustrate that bearing 111 is positioned between port on 155 of housing or cover 112 and extends along the axial for the purpose of providing a guide or bearing portion for bearing one end of thrust member 102 (or 2) and guide the same. The presser member is further supported by faces on member 155 or 112 at its other end.

FIGS. 16 and 17 show that to seal chamber 5 from chamber 6, a circular groove 87 can be formed in presser member 2 eccentrically to faces 7 and 8. A seal member 84 is inserted into groove 87, extends axially thereout and is pressed by fluid force in chamber 87 against face 567 of body 12. This simplifies the manufacture of pressure chambers 5 and 6 and the like. Pressure relieving spaces 88 are provided on one end of seal 84 and passages 85 or 86 which can contain check valves, transfer fluid under pressure into space 87. Groove 87 can be placed in passage body 2 (or 102) as shown or can be located in housing 12 (or 112).

FIG. 18 shows a control cylinder 89 with a reciprocating control piston 90 therein which alternatively, depending on pressure in passageways 92 and 93, opens or closes the access of these passageways to passage 91. Passage 92 and 93 can lead directly or indirectly to different control ports or fluid-containing chambers 5 or 6 in the machine and passage 91 can lead to a space in the machine which is to contain at all times the highest fluid pressure existing in the machine. For example, passage 91 can lead to space 87 of FIG. 16.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to be comprehended within the meaning and range of equivalence of the following claims.

What is claimed as new an desired to be protected by Letters Patent is set forth in the appended claims.

1. In a rotary fluid handling machine, in combination, housing means having a stepped inner annular shoulder surface; rotor means supported in said housing means for rotation about a rotor axis and for limited axial movement and having a rotary control face, said rotor means having working chambers, and movable displacement means in said working chambers having outer ends; actuator means having an inner annular surface engaged by said outer ends, said inner annular surface having an axis eccentric to said rotor axis so that said displacement means are moved in said working chambers for increasing and decreasing the volume of the respective working chamber, said displacement means assuming outer and inner end positions when moving through a predetermined plane passing through said axes; and a presser body means mounted in said housing means for limited axial movement, and having at one end thereof a stepped outer annular shoulder surface cooperating with said stepped inner annular shoulder surface of said housing means to form radially outer and inner annular pressure chambers containing high pressure fluid and low pressure fluid, respectively, for urging the other end of said presser body against said rotor means, said other end having a stationary control face which is pressed against said rotary control face, said outer annular pressure chamber being bounded at its outer periphery by pairs of cylindrical first face portions of said outer and inner stepped annular shoulder surfaces, said first face portions being coaxial with said rotor axis and slidingly engaging each other, said housing means having a cylindrical housing surface bounding the inner circumference of said inner annular pressure chamber, and said inner and outer annular pressure chambers being separated by second slidingly engaged cylindrical face portions of said inner and outer stepped annular shoulder surfaces, said second cylindrical face portions having a common axis eccentrically spaced from said rotor axis in a plane perpe ndicular to said predetermined plane passing through said rotor axis, said outer and inner stepped annular shoulder surfaces including outer and inner effective pressure faces located in planes perpendicular to said rotor axis between said slidingly engaged first and second cylindrical face portions and said cylindrical housing surface and having circumferentially varying widths so that narrow portions of said inner and outer pressure faces are located adjacent the wide portions of said outer and inner pressure faces, respectively.

2. A machine as claimed in claim 1 wherein said presser body has an oblong cross section bounded by part-circular surfaces to permit adjustment of said actuator ring means.

3. A machine as claimed in claim 1 wherein said rotor means include a first rotor having first working chambers and displacement means, a second rotor having second working chambers and displacement means, a first rotor shaft secured to said first rotor and having said rotor axis, said second rotor being mounted on said first rotor shaft for rotation, and a second hollow rotor shaft secured to said second rotor surrounding said first rotor shaft.

4. A machine as claimed in claim 3 comprising a tubular member mounted for rotation on said first and second shafts between said first and second rotors, and two annular control bodies located between the ends of said tubular member, and said first and second rotors, respectively, and slidingly engaging said ends and said first and second rotors.

5. A machine as claimed in claim 4 wherein said presser body means includes a presser body and another annular control body located between said presser body and said first rotor, wherein said second rotor has a rotary end face and said housing means has a stationary end face; and including a further annular control body located between said stationary and rotary end faces.

6. A machine as claimed in claim 24 wherein said housing means and said presser body form an annular counterbalancing chamber containing pressure fluid for biassing said pressure body away from said rotor means.

7. A machine as claimed in claim 25 wherein said presser body is tubular; and wherein said rotor means include a rotor shaft having said rotor axis and being surrounded by said tubular presser body.

8. In a rotary fluid handling machine, in combination, housing means having a stepped annular shoulder surface; rotor means supported in said housing means for rotation about a rotor axis and for limited axial movement and having a rotary control face, said rotor means having working chambers, and movable displacement means in said working chambers having outer ends; actuator means having an inner annular surface engaged by said outer ends, said inner annular surface having an axis eccentric to said rotor axis so that said displacement means are moved in said working chambers for increasing and decreasing the volume of the respective working chamber, said displacement means assuming outer and inner end positions when moving through a predetermined plane passing through said axes; and a presser body means mounted in said housing means for limited axial movement, and having at one end thereof a stepped outer annular shoulder surface cooperating with said stepped inner annular shoulder surface of said housing means to form radially outer and inner annular pressure chambers containing high pressure and low pressure fluid, respectively, for urging the other end of said presser body against said rotor means, said other end having a stationary control face which is pressed against said rotary control face, said outer annular pressure chamber being bounded at its outer periphery by pairs of cylindrical first face portions of said outer and inner stepped annular shoulder surfaces, said first face portions being coaxial with said rotor axis and slidingly engaging each other, means for restricting the radial inward extension of said inner annular pressure chamber, and said inner and outer annular pressure chambers being separated by second slidingly engaged cylindrical face portions of said inner and outer stepped annular shoulder surfaces, said second cylindrical face portions having a common axis eccentrically spaced from said rotor axis in a plane perpendicular to said predetermined plane passing through said rotor axis, said outer and inner stepped annular shoulder surfaces including outer and inner effective pressure faces located in planes perpendicular to said rotor axis between said slidingly engaged first and second cylindrical face portions and said restricting means, and having circumferentially varying widths so that narrow portions of said inner and outer pressure faces are located adjacent the wide portions of said outer and inner pres sure faces, respectively. 

1. In a rotary fluid handling machine, in combination, housing means having a stepped inner annular shoulder surface; rotor means supported in said housing means for rotation about a rotor axis and for limited axial movement and having a rotary control face, said rotor means having working chambers, and movable displacement means in said working chambers having outer ends; actuator means having an inner annular surface engaged by said outer ends, said inner annular surface having an axis eccentric to said rotor axis so that said displacement means are moved in said working chambers for increasing and decreasing the volume of the respective working chamber, said displacement means assuming outer and inner end positions when moving through a predetermined plane passing through said axes; and a presser body means mounted in said housing means for limited axial movement, and having at one end thereof a stepped outer annular shoulder surface cooperating with said stepped inner annular shoulder surface of said housing means to form radially outer and inner annular pressure chambers containing high pressure fluid and low pressure fluid, respectively, for urging the other end of said presser body against said rotor means, said other end having a stationary control face which is pressed against said rotary control face, said outer annular pressure chamber being bounded at its outer periphery by pairs of cylindrical first face portions of said outer and inner stepped annular shoulder surfaces, said first face portions being coaxial with said rotor axis and slidingly engaging each other, said housing means having a cylindrical housing surface bounding the inner circumference of said inner annular pressure chamber, and said inner and outer annular pressure chambers being separated by second slidingly engaged cylindrical face portions of said inner and outer stepped annular shoulder surfaces, said second cylindrical face portions having a common axis eccentrically spaced from said rotor axis in a plane perpendicular to said predetermined plane passing through said rotor axis, said outer and inner stepped annular shoulder surfaces including outer and inner effective pressure faces located in planes perpendicular to said rotor axis between said slidingly engaged first and second cylindrical face portions and said cylindrical housing surface and having circumferentially varying widths so that narrow portions of said inner and outer pressure faces are located adjacent the wide portions of said outer and inner pressure faces, respectively.
 2. A machine as claimed in claim 1 wherein said presser body has an oblong cross section bounded by part-circular surfaces to permit adjustment of said actuator ring means.
 3. A machine as claimed in claim 1 wherein said rotor means include a first rotor having first working chambers and displacement means, a second rotor having second working chambers and displacement means, a first rotor shaft secured to said first rotor and having said rotor axis, said second rotor being mounted on said first rotor shaft for rotation, and a second hollow rotor shaft secured to said second rotor surrounding said first rotor shaft.
 4. A machine as claimed in claim 3 comprising a tubular member mounted for rotation on said first and second shafts between said first and second rotors, and two annular control bodies located between the ends of said tubular member, and said first and second rotors, respectively, and slidingly engaging said ends and said first and second rotors.
 5. A machine as claimed in claim 4 wherein said presser body means includes a presser body and another annular control body located between said presser body and said first rotor, wherein saId second rotor has a rotary end face and said housing means has a stationary end face; and including a further annular control body located between said stationary and rotary end faces.
 6. A machine as claimed in claim 24 wherein said housing means and said presser body form an annular counterbalancing chamber containing pressure fluid for biassing said pressure body away from said rotor means.
 7. A machine as claimed in claim 25 wherein said presser body is tubular; and wherein said rotor means include a rotor shaft having said rotor axis and being surrounded by said tubular presser body.
 8. In a rotary fluid handling machine, in combination, housing means having a stepped annular shoulder surface; rotor means supported in said housing means for rotation about a rotor axis and for limited axial movement and having a rotary control face, said rotor means having working chambers, and movable displacement means in said working chambers having outer ends; actuator means having an inner annular surface engaged by said outer ends, said inner annular surface having an axis eccentric to said rotor axis so that said displacement means are moved in said working chambers for increasing and decreasing the volume of the respective working chamber, said displacement means assuming outer and inner end positions when moving through a predetermined plane passing through said axes; and a presser body means mounted in said housing means for limited axial movement, and having at one end thereof a stepped outer annular shoulder surface cooperating with said stepped inner annular shoulder surface of said housing means to form radially outer and inner annular pressure chambers containing high pressure and low pressure fluid, respectively, for urging the other end of said presser body against said rotor means, said other end having a stationary control face which is pressed against said rotary control face, said outer annular pressure chamber being bounded at its outer periphery by pairs of cylindrical first face portions of said outer and inner stepped annular shoulder surfaces, said first face portions being coaxial with said rotor axis and slidingly engaging each other, means for restricting the radial inward extension of said inner annular pressure chamber, and said inner and outer annular pressure chambers being separated by second slidingly engaged cylindrical face portions of said inner and outer stepped annular shoulder surfaces, said second cylindrical face portions having a common axis eccentrically spaced from said rotor axis in a plane perpendicular to said predetermined plane passing through said rotor axis, said outer and inner stepped annular shoulder surfaces including outer and inner effective pressure faces located in planes perpendicular to said rotor axis between said slidingly engaged first and second cylindrical face portions and said restricting means, and having circumferentially varying widths so that narrow portions of said inner and outer pressure faces are located adjacent the wide portions of said outer and inner pressure faces, respectively. 